I got familiar with the Northern lights family (originally said to be from the Pacific Northwest) back in the 1980's when Nevil's Seed Bank offered the whole lineup. The original Northern Lights family is genetically diverse.
Northern Lights 1 was a single stalked, compact plant with a moderate Afghani smell. No one offers this classic version at this time. A strong plant and buzz.
Northern Lights 2 was a sturdy, pine tree shaped with a musty and piney odor. Dutch Passion (Oasis) and THSeeds (Closet Queen) currently offer versions.
Northern Lights 2 X 5 from The Seed Bank was very bushy and resinous with a strong juniper berry smell. A truly remarkable hybrid not offered by anyone.
Northern Lights 5 is available from BCSC for $75, a variety Nevil of The Seed Bank said was only available pure as a cutting. It is likely hybridized at one point.
Northern Lights 9 X 5 "disappeared" when Nevil sold his genetics to Sensi Seeds. This is the only original Northern Lights 9 genetics source to my knowledge.
These are the original Northern Lights breeding lines from which today's versions arose. Sensi Seed Bank sells Northern Lights with no number attached. Having access to Nevil's original genetics, my guess is that they crossed an Northern Lights 1 male to their Northern Lights 5 mother and stabilized the results. Northern Lights Special is a hybrid from KC Brains in Holland of Sensi's Northern Lights crossed to a Haze female. Northern Lights 9 was only sold in seed form as a hybrid to the Northern Lights 5 mother plant by Nevil at The Seed Bank during the late 1980's. Sagarmatha receives a lot of their strains delivered to them as a finished product from outside breeders. It is possible that someone produced these seeds. The known fact of a Northern Lights 9 male existing meant purebred seed should have been possible to produce, unless it was a male only strain. Trichome Technologies has a strain named Northern Lights 6, another related family member.